Thank you, gravityhammer.
I did this to make the buttons work correctly with the keyboard:
put in /etc/apt/preferences:
Package: qt
Pin: version 1:3.3.3-8
Pin-Priority: 1000
run as root to downgrade qt to a MythTV-compatible version:
# apt-get install qt=1:3.3.3-8 qt-MySQL=1:3.3.3-8
# ldconfig
restart mythfrontend.
At the same time I put this in /etc/apt/preferences:
Package: urw-fonts
Pin: version 2.2*
Pin-Priority: 1000
and typed as root
# apt-get install urw-fonts
This made the dialogs fit the screen again (no more text outside the screen).
Hope this could help somebody
Nils Emil P. Larsen